Meeting Abstract
Enhancers are key regulators of gene expression; yet, the relationship between the structure of these important regulators and their evolution is little understood. To investigate this relationship, we studied early developmental cardiac enhancers of two species of tunicate, Corella inflata and Ciona intestinalis. Despite hundreds of millions of years of evolution and a high mutation rate, functional conservation of heart enhancers has been demonstrated between C. inflata and C. intestinalis. To determine whether the functional conservation translated to sequence level conservation of enhancers, we have begun analyzing the genome of the lesser known species, C. inflata. We first assembled the C. inflata genome using paired-end illumina data. We then isolated conserved heart enhancers, in particular we focused on FoxF, a gene necessary for heart progenitor cell migration in C. intestinalis. We performed sequence comparison of the C. inflata and C. intestinalis FoxF enhancers, and found conservation in both the composition and order of transcription factor binding sites. We tested the functionality of each of these binding sites using reporter analysis. Our results demonstrate both sequence-level and functional conservation of this enhancer. We plan to further characterize conserved heart gene expression patterns using in situ hybridization and to perform more sequence analysis using recently-collected RNAseq data to better characterize the relationship between enhancer function, structure and evolution.
